Subjects -> INSTRUMENTS (Total: 63 journals)
Showing 1 - 16 of 16 Journals sorted by number of followers
International Journal of Remote Sensing     Hybrid Journal   (Followers: 161)
IEEE Sensors Journal     Hybrid Journal   (Followers: 119)
Remote Sensing of Environment     Hybrid Journal   (Followers: 96)
Journal of Applied Remote Sensing     Hybrid Journal   (Followers: 87)
Modern Instrumentation     Open Access   (Followers: 58)
Remote Sensing     Open Access   (Followers: 57)
International Journal of Remote Sensing Applications     Open Access   (Followers: 48)
International Journal of Instrumentation Science     Open Access   (Followers: 42)
Experimental Astronomy     Hybrid Journal   (Followers: 39)
Measurement and Control     Open Access   (Followers: 36)
Photogrammetric Engineering & Remote Sensing     Full-text available via subscription   (Followers: 34)
Journal of Instrumentation     Hybrid Journal   (Followers: 32)
Remote Sensing Science     Open Access   (Followers: 30)
Applied Mechanics Reviews     Full-text available via subscription   (Followers: 27)
Review of Scientific Instruments     Hybrid Journal   (Followers: 20)
European Journal of Remote Sensing     Open Access   (Followers: 17)
Videoscopy     Full-text available via subscription   (Followers: 15)
Flow Measurement and Instrumentation     Hybrid Journal   (Followers: 15)
Transactions of the Institute of Measurement and Control     Hybrid Journal   (Followers: 12)
Journal of Sensors and Sensor Systems     Open Access   (Followers: 11)
Remote Sensing Applications : Society and Environment     Full-text available via subscription   (Followers: 9)
Instrumentation Science & Technology     Hybrid Journal   (Followers: 8)
International Journal of Applied Mechanics     Hybrid Journal   (Followers: 8)
Imaging & Microscopy     Hybrid Journal   (Followers: 7)
Microscopy     Hybrid Journal   (Followers: 7)
Metrology and Measurement Systems     Open Access   (Followers: 7)
Science of Remote Sensing     Open Access   (Followers: 7)
Optoelectronics, Instrumentation and Data Processing     Hybrid Journal   (Followers: 6)
International Journal of Metrology and Quality Engineering     Full-text available via subscription   (Followers: 5)
Measurement : Sensors     Open Access   (Followers: 5)
PFG : Journal of Photogrammetry, Remote Sensing and Geoinformation Science     Hybrid Journal   (Followers: 5)
Computational Visual Media     Open Access   (Followers: 5)
Journal of Medical Devices     Full-text available via subscription   (Followers: 4)
Sensors and Materials     Open Access   (Followers: 4)
IEEE Sensors Letters     Hybrid Journal   (Followers: 4)
Journal of Astronomical Instrumentation     Open Access   (Followers: 4)
Journal of Optical Technology     Full-text available via subscription   (Followers: 4)
IEEE Journal on Miniaturization for Air and Space Systems     Hybrid Journal   (Followers: 3)
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems)     Open Access   (Followers: 3)
Sensors International     Open Access   (Followers: 3)
Solid State Nuclear Magnetic Resonance     Hybrid Journal   (Followers: 3)
Measurement Techniques     Hybrid Journal   (Followers: 3)
Journal of Instrumentation Technology & Innovations     Full-text available via subscription   (Followers: 3)
International Journal of Sensor Networks     Hybrid Journal   (Followers: 2)
International Journal of Measurement Technologies and Instrumentation Engineering     Full-text available via subscription   (Followers: 2)
Geoscientific Instrumentation, Methods and Data Systems     Open Access   (Followers: 2)
International Journal of Testing     Hybrid Journal   (Followers: 1)
Medical Devices & Sensors     Hybrid Journal   (Followers: 1)
Instruments and Experimental Techniques     Hybrid Journal   (Followers: 1)
Geoscientific Instrumentation, Methods and Data Systems Discussions     Open Access   (Followers: 1)
Journal of Research of NIST     Open Access   (Followers: 1)
Journal of Vacuum Science & Technology B     Hybrid Journal   (Followers: 1)
Invention Disclosure     Open Access   (Followers: 1)
Metrology and Instruments / Метрологія та прилади     Open Access  
Measurement Instruments for the Social Sciences     Open Access  
Труды СПИИРАН     Open Access  
Standards     Open Access  
Jurnal Informatika Upgris     Open Access  
InfoTekJar : Jurnal Nasional Informatika dan Teknologi Jaringan     Open Access  
Devices and Methods of Measurements     Open Access  
EPJ Techniques and Instrumentation     Open Access  
Journal of Medical Signals and Sensors     Open Access  
Documenta & Instrumenta - Documenta et Instrumenta     Open Access  
Similar Journals
Journal Cover
Journal of Vacuum Science & Technology B
Journal Prestige (SJR): 0.467
Citation Impact (citeScore): 1
Number of Followers: 1  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 2166-2746 - ISSN (Online) 2166-2754
Published by AVS Homepage  [2 journals]
  • Influence of thermal contact resistance on the field emission
           characteristics of a carbon nanotube

    • Free pre-print version: Loading...

      Authors: Jonathan Ludwick, Nathaniel Hernandez, Geet Tripathi, Marc Cahay, Tyson Back, Kevin L. Jensen
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      A recent algorithm developed by Tripathi et al. [J. Appl. Phys. 128, 025017 (2020); Erratum, J. Appl. Phys. 131, 169901 (2022)] is modified to study the effects of thermal contact resistance on the field emission (FE) properties of a carbon nanotube (CNT). The model takes into account the temperature dependence of the CNT electrical and thermal conductivities. The boundary condition proposed by Huang et al. [Phys. Rev. Lett. 93, 7 (2004)] is used to include the effects of thermal contact resistance at a CNT/chuck interface located at [math], i.e., [math], where r is the CNT radius, [math] is the heat conduction coefficient at [math], and [math] is the thermal resistivity of the CNT/chuck interface. The chuck is assumed to be a perfect heat sink at temperature [math]. For a given set of CNT parameters and values of the applied external electric field, it is shown that current constriction at the CNT/chuck contact point leads to self-heating effects which increase with the value of the thermal contact resistance, leading to an increase in the temperature profile along the CNT (including the temperature at its tip) and the FE current above their values obtained assuming the CNT/chuck interface is at the heat sink temperature [math]. The fractional change of the emission current versus applied external electric field is calculated for increasing values of the parameter [math].
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-07-18T12:09:24Z
      DOI: 10.1116/6.0002001
       
  • Outgassing rate testbed for in-operation analysis of powered and heated
           assemblies

    • Free pre-print version: Loading...

      Authors: Marvin Warner, Michael Elsen, Lisa Wörner, Claus Braxmaier, Jens Grosse
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      We introduce a new apparatus for measuring the outgassing rate of assemblies and functional units. Outgassing rates given in the literature, if available, are mostly insufficient to plan and set up a vacuum system, more so if commercial parts, preassembled items, or complex electronics with unknown components are deployed. Outgassing rates have a severe impact on the required pumping speed in ultrahigh vacuum systems and they change if the samples are powered or heated. The newly built apparatus uses the throughput method to measure outgassing rates. It can house probes with a size of [math] and supplies electrical currents of up to 5 A. In addition, a heater can establish temperatures of up to 200 [math]C directly. A procedure is given to identify the main gas inputs and to retrieve data with a lower limit of [math] after 100 h in vacuum. In this paper, we present the experimental setup and first results for samples of polytetrafluorethylene, polyamide (PA6), Viton (1A), and oxygen-free high thermal conductivity copper at room temperature.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-07-13T11:18:45Z
      DOI: 10.1116/6.0001898
       
  • Design of the vacuum-centralized control system for the space plasma
           environment research facility based on the Experimental Physics and
           Industrial Control System

    • Free pre-print version: Loading...

      Authors: Chenggang Jin, Yongqi Zhang, Wenbin Ling, Xinglin Yang, Jiangnan Cheng, Li Feng, Jie Wan, Huan Wang, Yaowen Lu, Liyi Li, Peng E.
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      The Space Plasma Environment Research Facility (SPERF) is a ground-simulation facility, which is under construction, for studying space plasma. It includes a terrestrial space plasma environment simulation system (T-S system) and near-space plasma environment simulation system (N-S system). Plasma experiments performed on the SPERF require the functional cooperation of each subsystem. Therefore, the Experimental Physics and Industrial Control System (EPICS) was selected as the middleware in the engineering phase. Currently, the architecture of a vacuum-centralized control system is almost complete, and it is in the process of debugging. The application of EPICS in the SPERF vacuum-centralized control system has laid a structural foundation for the integration of other control systems and provides a test bed. In this study, we describe the implementation of EPICS for the SPERF vacuum-centralized control system, a procedure from hardware drivers realizing operation panels.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-07-07T12:16:32Z
      DOI: 10.1116/6.0001931
       
  • Hollow cathode enhanced capacitively coupled plasmas in Ar/N2/H2 mixtures
           and implications for plasma enhanced ALD

    • Free pre-print version: Loading...

      Authors: David R. Boris, Michael J. Johnson, Charles R. Eddy, Scott G. Walton
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      Plasma enhanced atomic layer deposition (PEALD) is a cyclic atomic layer deposition process that incorporates plasma-generated species into one of the cycle substeps. The addition of plasma is advantageous as it generally provides unique gas-phase chemistries and a substantially reduced growth temperature compared to thermal approaches. However, the inclusion of plasma, coupled with the increasing variety of plasma sources used in PEALD, can make these systems challenging to understand and control. This work focuses on the use of plasma diagnostics to examine the plasma characteristics of a hollow cathode enhanced capacitively coupled plasma (HC-CCP) source, a type of plasma source that has seen increasing attention in recent years for PEALD. Ultraviolet to near-infrared spectroscopy as well as spatially resolved Langmuir probe and emissive probe measurements are employed to characterize an HC-CCP plasma source using nitrogen based gas chemistries typical of nitride PEALD processes. Spectroscopy is used to characterize the relative concentrations of important reactive and energetic neutral species generated in HC-CCP systems as a function of applied RF power, gas chemistry, and pressure. In addition, the electron energy distribution function, electron temperature, plasma potential, and plasma density for the same process parameters are examined using an RF compensated Langmuir probe and emissive probe. These measurements indicated that electron temperature (Te), electron density (ne), and plasma potential (Vp) varied significantly over the operating conditions examined with Te varying from 1.5 to 8 eV, Vp varying from 30 to 90 V, and ne varying between 1015 and low 1016 m−3. This wide range of plasma conditions is mediated by a mode transition from a low Te, high ne mode of operation at low pressure (100 mTorr). These operational modes appear analogous to the classical γ and α modes of traditional capacitively coupled plasmas. Atomic N and H densities also vary significantly over the operating conditions examined.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-07-01T01:09:19Z
      DOI: 10.1116/6.0001840
       
  • Enhanced optoelectronic properties of magnetron sputtered ITO/Ag/ITO
           multilayers by electro-annealing

    • Free pre-print version: Loading...

      Authors: Zemzem Uyanik, Fulya Turkoglu, Hasan Koseoglu, Merve Ekmekcioglu, Bengu Ata, Yasemin Demirhan, Mehtap Ozdemir, Gulnur Aygun, Lutfi Ozyuzer
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      Indium tin oxide/silver/indium tin oxide (ITO/Ag/ITO) multilayers have attracted much attention to fulfill the growing need for high-performance transparent conducting oxide electrodes. To make these transparent multilayers work better, electro-annealing, which is a method of self-heating by electric current, can be effective. Moreover, the effect of current on ITO/Ag/ITO multilayers should be investigated to make sure that electronic devices will be reliable over their lifetime. In this study, ITO/Ag/ITO multilayer electrodes with varying Ag thicknesses were grown by DC magnetron sputtering at room temperature. Structural, optical, and electrical properties of these multilayers were investigated before and after electro-annealing. Measurement results revealed that improved optical transmittance and sheet resistance can be obtained by the optimization of Ag thickness for the as-grown ITO/Ag/ITO layers. The highest figure of merit (FoM) value of 17.37 × 10−3 Ω−1 with optical transmittance of 85.15% in the visible region and sheet resistance of 11.54 Ω/□ was obtained for the Ag thickness of 16.5 nm for as-grown samples. The electro-annealing of as-grown ITO/Ag/ITO multilayers led to improved optical behavior of the multilayer structure over a wide spectral range, especially in the near-infrared range. Electro-annealing also provided an improvement in the crystallinity and sheet resistance of the electrodes. The improvement of the electrical and optical properties of the structure enabled a FoM of 23.07 × 10−3 Ω−1 with the optical transmittance of 86.80% in the visible region and sheet resistance of 10.52 Ω/□. The findings of this work provide proper knowledge of the properties of ITO/Ag/ITO multilayers under electrical current and suggest that the overall performance of the multilayers can be improved by the electro-annealing process.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-06-30T11:14:22Z
      DOI: 10.1116/6.0001868
       
  • Scanning anode field emission microscopy of a single Si emitter

    • Free pre-print version: Loading...

      Authors: Girish Rughoobur, Olusoji O. Ilori, Akintunde I. Akinwande
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      Emitter tip radius nonuniformity results in exponential variations in emission current and a relatively low array utilization. Here, we provide a method of mapping the current and field-factor from a single emitter over a small area using a scanning anode field emission microscope. A dull W probe is used as the anode, and an array of emitters is fabricated on silicon (Si) wafers. We use a relatively wide spaced (100 [math]m pitch) emitter array with each emitter having an integrated Si pillar. Current-voltage characteristics are used to extract the field-factor and to experimentally demonstrate the mapping of the currents and field-factor of a single emitter. From emission spot sizes, the emission half-angles are measured to be [math] at anode voltages 2.5 kV and a minimum resolvable feature of 2–3 [math]m at 1.8 kV. We also determine the field-factor dependence with the distance between the anode and the emitter, where limiting the current becomes essential to prevent early burn-out of the emitter that could reduce the current. We also simulated the maximum currents tolerated by the pillar to assess the thermal effects on the emitter. Finite element modeling confirms the experimental trend in the field-factor with the distance between the anode and the emitter tip, resulting in a value of approximately [math] cm[math] for an emitter tip radius of 5 nm and an emitter-anode distance of 50 [math]m.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-06-29T11:42:37Z
      DOI: 10.1116/6.0001938
       
  • On modeling the induced charge in density-functional calculations for
           field emitters

    • Free pre-print version: Loading...

      Authors: S. M. Masur, C. J. Edgcombe, C. H. W. Barnes
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      The default assumption of many density-functional theory codes that the simulation cell is spatially periodic implies that any unbalanced charge in the cell will cause the solution to diverge, unless the imbalance is removed in some unphysical way. Periodic solution thus makes it difficult to model accurately the charge and field that are induced at the apex of a single carbon nanotube (CNT) when a background electric field is applied. We describe how the charge induced in a single cell containing 1.8 nm of the capped end of a (5,5) CNT can be calculated from a macroscopic model of the CNT with an external field acting on the whole CNT. With this method, a cell containing the CNT tip has been analyzed using the program ONETEP, a linear-scaling code that iterates the density kernel and the localized orbitals self-consistently to minimize the Helmholtz free energy. The results shown include (1) the sheath of mobile charge outside the framework of nuclei; (2) Kohn–Sham (KS) orbitals including the localized end states that are occupied when the field is applied; (3) total effective potential distribution as a function of the applied field; and (4) an induced field-enhancement factor of 50 deduced from the change of potential with the applied field. The computation also shows that (5) the charge density in zero field extends into the potential barrier over a distance of at least 0.12 nm beyond the Fermi equipotential, consistent with KS theory for the boundary between emitter and barrier.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-06-28T11:39:25Z
      DOI: 10.1116/6.0001886
       
  • Study of simulations of double graded InGaN solar cell structures

    • Free pre-print version: Loading...

      Authors: Mirsaeid Sarollahi, Mohammad Zamani-Alavijeh, Rohith Allaparthi, Manal A. Aldawsari, Malak Refaei, Reem Alhelais, Md Helal Uddin Maruf, Yuriy I. Mazur, Morgan E. Ware
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      The performances of various configurations of InGaN solar cells are compared using nextnano semiconductor simulation software. Here, we compare a flat base-graded wall GaN/InGaN structure, with an InxGa1−xN well with sharp GaN contact layers, and an InxGa1−xN structure with InxGa1−xN contact layers, i.e., a homojunction. The doping in the graded structures is the result of polarization doping at each edge (10 nm from each side) due to the compositional grading, while the well structures and homojunctions are impurities doped at each edge (10 nm from each side) at levels equal to the polarization doping density in the graded structure with similar maximum indium concentration. The solar cells are characterized by their open-circuit voltage, Voc, short circuit current, Isc, solar efficiency, η, and energy band diagram. The results indicate that an increase in Isc and η results from increasing both the fixed and maximum indium compositions, while the Voc decreases. The maximum efficiency is obtained for the InGaN well with 60% In.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-06-27T12:10:57Z
      DOI: 10.1116/6.0001841
       
  • Device feasibility and performance improvement methodologies for thin film
           

    • Free pre-print version: Loading...

      Authors: Shin-Ho Noh, Hyo-Eun Kim, Young-Ha Kwon, Nak-Jin Seong, Kyu-Jeong Choi, Sung-Min Yoon
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      Thin film transistors (TFTs) using In-Ga-Sn-O (IGTO) active channel layers, which were prepared by atomic-layer deposition (ALD) techniques, were fabricated and characterized with exploring the optimum IGTO channel compositions and the process conditions for the formation of gate-stack structures. The introduction of an O3 oxidant was confirmed to secure a wider process window, which was explained by hydrogen incorporation from the protection layer/gate insulator stacked layers into the IGTO active channel. The cationic compositions of the IGTO thin films were controlled by subcyclic ratio design of each precursor. When the number of In-Ga precursor subcycles increased from 4 to 6, the Ga/Sn ratio increased from 3.5 to 4.0, leading to marked improvements in the VON characteristics of the fabricated IGTO TFTs. It was found from a comparative analysis on the device characteristics that the Ga/Sn ratio in the IGTO channel had a more dominant effect on the VON characteristics rather than the In/Ga ratio. The device using the channel with a cationic composition of 5.8:4.0:1.0 (In:Ga:Sn) exhibited the field-effect mobility of 19.1 cm2/V s, the subthreshold swing of 0.22 V/dec, and the threshold voltage (VTH) of 0.22 V, which corresponded to the best device characteristics among the fabricated devices. Furthermore, the VTH shifts were examined to be +0.4 and −0.4 V in positive and negative bias stress conditions, respectively, demonstrating excellent gate-bias stress stabilities. The obtained results suggest the device feasibility and fabrication process validity for the TFT applications using IGTO active channel layers prepared by ALD techniques.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-06-24T10:11:30Z
      DOI: 10.1116/6.0001945
       
  • Theoretical research on suppression ratio of dynamic gas lock for extreme
           ultraviolet lithography contamination control

    • Free pre-print version: Loading...

      Authors: Jiazheng Sun, Kuibo Wang, Xiaobin Wu, Yan Luo, Jinbin Ding
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      Dynamic gas lock (DGL) is an important technology for contamination control of extreme ultraviolet (EUV) lithography. DGL prevents contamination diffusion from the dirty compartment into the clean one and allows passage of EUV light between compartments. A number of DGL structures have been proposed for EUV scanners. The suppression ratio is the key index of DGL, but there are few theoretical studies on it. Using the Péclet number to represent the suppression ratio just ignores the variable cross section of DGL and the effect of the total mass flow. A new suppression ratio formula is derived here based on the convection-diffusion equation, including the constant and variable cross section of DGL. In order to verify the theoretical calculation, an experiment is carried out on a self-developed DGL device, obtaining the gas flow utilization and suppression ratio of various mass flows. The results show that the suppression ratio increases exponentially with mass flow, which is consistent with the theoretical expectation. At the same time, the important influence of the convection segment has also been demonstrated. It is concluded that the theoretical approach can well predict the suppression ratio and provide structural design guidance for DGL, which has an important practical application value.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-06-22T11:20:37Z
      DOI: 10.1116/6.0001852
       
  • Resistive switching of two-dimensional Ag2S nanowire networks for
           neuromorphic applications

    • Free pre-print version: Loading...

      Authors: Mahshid Hosseini, Nikolay Frick, Damien Guilbaud, Ming Gao, Thomas H. LaBean
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      Randomly assembled networks of nanowires (NWs) can display complex memristive behaviors and are promising candidates for use as memory and computing elements in neuromorphic applications due to device fault tolerance and ease of fabrication. This study investigated resistive switching (RS) in two-dimensional, self-assembled silver sulfide (Ag2S) NW networks first experimentally and then theoretically using a previously reported stochastic RS model. The simulated switching behavior in these networks showed good correlation with experimental results. We also demonstrated fault-tolerance of a small NW network that retained RS property despite being severely damaged. Finally, we investigated information entropy in NW networks and showed unusual dynamics during switching as a result of self-organization of the memristive elements. The results of this work provide insights toward physical implementation of randomly assembled RS NW networks for reservoir and neuromorphic computing research.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-06-13T12:48:24Z
      DOI: 10.1116/6.0001867
       
  • Simplified CVD route to near-zero thickness silicon nitride films

    • Free pre-print version: Loading...

      Authors: Barry Arkles, Chad Brick, Jonathan Goff, Alain E. Kaloyeros
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      Silicon nitride (SiNx, x ∼ 1) thin films were deposited by chemical vapor deposition on silicon oxide (SiO2) substrates by combining controlled pulses of the precursor 1,3,5-tri(isopropyl)cyclotrisilazane (TICZ, C9H27N3Si3) with a continuous ammonia (NH3) plasma. This plasma-assisted pulsed CVD (PPCVD) process enables the integration of the nanoscale thickness and uniformity control achieved in atomic layer deposition with the efficiency of plasma-enhanced CVD (PE-CVD). TICZ was selected because it is a nonpyrophoric stable liquid with a high vapor pressure (∼133 Pa at 70 °C) and could act as a single source for SiNx with both high Si and N contents. An optimized PPCVD process window was identified consisting of a substrate temperature of 350 °C, a TICZ pulse of ≤0.2 s, and a TICZ purge pulse ≥10 s in a continuous direct NH3 plasma at a NH3 flow rate and a power of 40 SCCM and 3000 W, respectively. The as-deposited films were analyzed by x-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry. XPS analysis confirmed the absence of any C inclusion and demonstrated the existence of the 1:1 Si:N ratio. In situ, real-time ellipsometry measurements indicated that SiNx growth occurred in a typical PE-CVD regime. They also yielded an as-grown SiNx average refractive index of ∼1.75.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-06-03T12:38:10Z
      DOI: 10.1116/6.0001820
       
  • ZnO piezoelectric coatings used for the ultrasonic excitation of
           longitudinal-transverse waves and their application for smart bolts

    • Free pre-print version: Loading...

      Authors: Yanghui Jiang, Jingyu Li, Guangming Jiao, Wensheng Li, Yan Liu, Chuan Wang, Binhong Xia, Binhua Wan, Jun Zhang, Vasiliy Pelenovich, Sheng Liu, Bing Yang
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      The accurate measurement of the prestress for bolt has been intensively investigated in recent years. Many research studies have been conducted to improve the accuracy of prestress measurement using ultrasound techniques; in particular, the real-time prestress of bolt can be obtained without the requirements to calibrate the original load when ultrasonic longitudinal and transverse waves are applied simultaneously. However, there are few studies that have focused on ultrasonic transducers that can generate longitudinal and transverse waves simultaneously. Furthermore, research on coatings deposited directly on the top of the bolts for the excitation of longitudinal and transverse waves has not been reported. ZnO coating is widely used for the ultrasonic transducer due to its excellent piezoelectric property and stable structure in high temperatures. Therefore, it is an outstanding candidate for the excitation of both longitudinal and transverse waves and has a good application prospect in the field of bolt prestress measurement by ultrasonic sound wave with high accuracy. In this paper, ZnO piezoelectric coatings were deposited on (100)-oriented Si substrates by radio frequency sputtering techniques. The morphology, structure, and echo signal characteristics of the coatings were characterized by SEM, AFM, XRD, and ultrasonic measurement instruments. The experimental results showed that Ar/O2 ratio and deposition position exhibited significant effects on the excitation waveform of the ZnO piezoelectric coating. When the Ar/O2 ratio reduced to 1:3, the coating could excite both transverse and longitudinal waves. However, when the deposition position gradually moved away from the sputtering center, the transverse wave gradually enhanced. The coating could excite a pure transverse wave when the sample was at the edge of the effective sputtering area, which showed that the type of the excitation wave and the relative intensity of each wave could be well controlled by the Ar/O2 ratio and deposition position. These research results have a good application prospect in bolt stress measurement.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-06-03T12:38:10Z
      DOI: 10.1116/6.0001845
       
  • Investigation of Rb+ milling rates using an ultracold focused ion beam

    • Free pre-print version: Loading...

      Authors: S. Xu, Y. Li, E. J. D. Vredenbregt
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      Several ion source alternatives for current focused ion beam (FIB) systems have been studied to achieve higher brightness, including cold atom ion sources. However, a study of ultracold ions interacting with often used materials is seldom reported. Here, we investigate milling on several typical samples in a prototype ultracold Rb FIB system at 8.5 keV beam energy. For polycrystalline metallic substrates, such as Cu and Au, patterns milled by [math] ions are observed to have reduced surface roughness but still high milling rates compared with those milled by [math] ions. [math] also shows similar sputter rates as 30 keV [math] on semiconductor substrates GaAs and InP. Special cases for [math] milling show that the [math] ion beam has a [math] faster sputter rate on diamond but a [math] slower sputter rate on Al compared with a normal 30 keV [math] ion beam. In general, an [math] ion beam is shown to be suitable for nanostructuring of several basic materials.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-06-02T11:38:39Z
      DOI: 10.1116/6.0001838
       
  • Seesaw-type modulation of secondary electron emission characteristics of
           polytetrafluoroethylene-MgO composite coating

    • Free pre-print version: Loading...

      Authors: Yahui Cai, Dan Wang, Wen Zhang, Yongning He
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      The electrostatic discharge (ESD) from polymer insulators is one of the environment-related anomalies on spacecraft. Theoretically, to mitigate the ESD effects, we could modulate the secondary electron yield (SEY, σ) close to 1 in the entire energy range, suppressing surface charges. However, no single polymer insulator has been reported to achieve this seesaw-type modulation of SEY. Here, we exploringly designed and prepared MgO particles doped polytetrafluoroethylene (PTFE) composite coating to achieve this goal, which exhibits not only the reduced SEY characteristic of the microstructured PTFE coating at low energy but also the enhanced SEY characteristic of the double-layer structure of PTFE and MgO at high energy. The simulation and experiment results demonstrate that MgO particles doped PTFE coating achieves this seesaw-type modulation of SEY. The optimal MgO concentration is 20%, where the maximum SEY (σmax) changes from 2.0 to 1.1; the SEY at 10 keV (σ10k) changes from 0.6 to 0.8, and the higher energy of the SEY equal to 1 (Ep2) increases from 4.5 to 6.5 keV. The discharge test of the microstrip antennas with PTFE-MgO composite coating in a scanning electron microscope verifies the role of the seesaw-type SEY modulation in surface charge suppression. This study supplies an essential reference for suppressing surface charges on vacuum electronics based on modulation of secondary electron emission characteristics.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-06-02T11:38:38Z
      DOI: 10.1116/6.0001921
       
  • Integrated interferometry for in-process monitoring of critical dimension
           in vertical NAND flash memory dry etch

    • Free pre-print version: Loading...

      Authors: Se-Jin Oh
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      Integrated interferometry installed on top of dry etch equipment was developed for the in-process measurement of critical dimension (CD) in vertical NAND flash memory dry etch forming word-line steps, also known as word-line processes. The etching process sequentially consists of mask trimming and mold etching (multilayered structure of Si3N4 and SiO2). In-process real-time CD measurements can be made in a trimming step that etches the photoresist (PR) to form a vertical mask shape. The measurement principle is based on the analysis of the interference fringe signal of light reflection to a single point in the center of the wafer. To check the measurement accuracy of the interferometer, the CD measured with interferometry was compared with an in-line SEM (scanning electron microscope). The correlation coefficient between the interferometric measurements measured during the mask trimming step and the in-line SEM measured after the completed process was 86%. On the other hand, when the mask trimming and the mold etching steps including Si3N4 over etching were added, the total measurement results showed that the correlation coefficient was 95%. This is because the CD value was derived based on the phenomenon that the PR thickness change measured by interferometry in the trimming step was a linear relationship with the change in the lateral PR amount, so the lateral PR amount was weakly etched in the mold etching step after the trimming step, which eventually affected the final formed CD. This metrology method can be simply applied to dry etching equipment in real production lines.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-05-31T12:37:38Z
      DOI: 10.1116/6.0001883
       
  • Design and fabrication of a micro-opto-mechanical-systems accelerometer
           based on intensity modulation of light fabricated by a modified
           deep-reactive-ion-etching process using silicon-on-insulator wafer

    • Free pre-print version: Loading...

      Authors: Reza Gholamzadeh, Milad Gharooni, Hassan Salarieh, Javad Akbari
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      Accelerometers that work based on intensity modulation of light are more sensitive, economically feasible, and have a simpler fabrication process compared to wavelength modulation. A micro-opto-electro-mechanical-system accelerometer based on intensity modulation of light is designed and fabricated. A movable shutter that is attached to the proof mass is designed to change the intensity of light. Moreover, the mechanical part is designed to improve the overall sensitivity and linear behavior in the measurement range. The designed accelerometer is fabricated by a deep-reactive-ion-etching (DRIE) process. The DRIE process used in this report is based on a Bosch-like process, which uses [math] and a mixture of [math], [math], and [math] gases in etching and passivation subsequences, respectively. This method has a lower plasma density and a higher base pressure and causes higher verticality, which results in lower optical efficiency loss in comparison with the Bosch process. Furthermore, the functional characteristics of the accelerometer are derived with analytical and numerical methods, and the results are compared. The functional characteristics of the accelerometer are as follows: a resonant frequency of 0.56 kHz, a mechanical sensitivity of [math], an optical sensitivity of [math], an overall sensitivity of [math], a footprint of [math], a measurement range of [math], a mechanical cross axis sensitivity of [math], and an overall cross axis sensitivity of [math]. These functional characteristics make the design appropriate for a large range of applications.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-05-31T12:37:35Z
      DOI: 10.1116/6.0001779
       
  • Stochastic defect removal coating for high-performance extreme ultraviolet
           lithography

    • Free pre-print version: Loading...

      Authors: Young Joo Choi, Ran Namgung, Jun Soo Kim, Dae Seok Song, Hyeon Park, Shin-hyo Bae, Min-Ki Chon, Min Soo Kim, Hyun-Ji Song, Hyun-Woo Kim, Suk Koo Hong
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      To reduce the stochastic defect caused by insufficient photon numbers of extreme ultraviolet lithography, a simple additional process has been designed and experimented. The additional process consists of one coating and washing process after pattern formation by lithography. The coating material was named stochastic defect removal coating and was carefully designed to reduce the stochastic defects without harming the lithographic margin. The defect reduction up to 48% was accomplished by failure-free latitude measurement and defect inspection.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-05-25T12:23:47Z
      DOI: 10.1116/6.0001723
       
  • Influence of the electron kinetics on Ar/NF3 inductively coupled plasma

    • Free pre-print version: Loading...

      Authors: Dmitry Levko, Laxminarayan L. Raja
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      A self-consistent two-dimensional axisymmetric fluid plasma model coupled with Maxwell's equations is used to analyze the plasma kinetics of inductively coupled Ar/NF3 low-pressure plasma. We have developed a plasma chemical reaction mechanism for Ar/NF3 plasma and validated the same against the experimental data found in the literature. We analyze two sets of the electron-neutral reaction rate coefficients obtained for assumed Maxwellian and non-Maxwellian electron energy distribution functions. We find that the electron density in the discharge is sensitive to the choice of the electron energy distribution, while the fluorine atoms density is less sensitive. Since the density of atoms is controlled by a balance between production by dissociation reactions and diffusion to the walls, their density is very sensitive to the wall sticking probability.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-05-24T12:41:52Z
      DOI: 10.1116/6.0001906
       
  • Effects of iCVD organic passivation in oxide thin-film transistors under
           repetitive bending stress for electrical and mechanical stability

    • Free pre-print version: Loading...

      Authors: Taeseung Jung, Sanghun Jeon
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      The passivation layers that should be formed on flexible electronics devices require high mechanical stability. Therefore, organic passivation has been used to enhance the electrical characteristics of various devices such as thin-film transistors (TFTs), organic light emitting diodes, and capacitors under mechanical stress. However, the conventional deposition of an organic film based on spin coating results in excessive thickness and the potential for chemical damage due to by-products such as organic solvents throughout the process. Here, we present the effects of a poly(1,3,5-trimethyl-1,3,5-trivinyl cyclotrisiloxane) organic passivation layer deposited by initiative chemical vapor deposition (iCVD) on the electrical and mechanical stabilities of oxide TFTs subjected to 30 000 repetitive tensile bending cycles. The highly ultrathin (50 nm) and excellent roughness (Rq = 0.33 nm) of the pV3D3 film assisted in preserving the mechanical stability of the device under external mechanical stress, and degradation of the electrical properties was suppressed compared with a device using SiO2 passivation. The mechanical properties of the type of passivation layer, including its Young’s modulus, affected the degradation of the electrical properties and reliability characteristics under repetitive bending. Finite-element structural simulations indicated a 15% reduction in equivalent stress applied to each layer of the device when pV3D3 (versus SiO2 passivation) was used. The iCVD-deposited pV3D3 film used in this study is a powerful candidate to act as the passivation layer of flexible electronics by strengthening the electrical stability of a device under external mechanical stress.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-05-24T12:41:51Z
      DOI: 10.1116/6.0001800
       
  • Overlay control solution for high aspect ratio etch process induced
           overlay error

    • Free pre-print version: Loading...

      Authors: Enze Ma, Libin Zhang, Yaobin Feng, Le Ma, Shixin Zhang, Yayi Wei
      Abstract: Journal of Vacuum Science & Technology B, Volume 40, Issue 4, July 2022.
      In the semiconductor manufacturing process, especially in the high aspect ratio etch process of 3D NAND, overlay remains a constraint in an increasing device yield. With the increase in 3D layers, the etch process shows extreme inconsistency for different lots with different etch chambers, which makes it difficult to control within the budget. This article gives a systematic analysis on how the overlay feedback model reduces the overlay and which method should be used to reduce the etch-induced overlay residue. The linear and nonlinear inter- and intrafield models are used, and the overlay reduction performance is limited. Then, a correction per exposure (CPE) method is used, which shows the minimum residue. The feedforward overlay method together with the linear and nonlinear CPE method shows the best performance with only 20%–30% overlay residue. Two methods are recommended during the CPE model applied to control overfitting. One is to choose the best CPE order by judging the mark number of each exposure field, and the other is to define the fitting parameter range in a suitable range. Different CPE models are used and compared, and the verification results demonstrate that the suggested method has a great overlay fitting performance and overlay residue even if some parameters are excluded. That is, the study shows a method to balance the process variation, machine performance, feedback model, and metrology data.
      Citation: Journal of Vacuum Science & Technology B
      PubDate: 2022-05-23T12:26:37Z
      DOI: 10.1116/6.0001814
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 44.200.175.255
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-